泥螺生殖系统的组织学

泥螺为雌雄同体。生殖系统包括交媾器和生殖器本部。交媾器包括刺激器、阴茎和摄护腺；生殖器本部主要包括两性腺、缠卵腺和蛋白腺。刺激器和阴茎都具有非常发达的肌肉组织，腔壁游离面具纤毛。阴茎腔壁为单层柱状细胞；摄护腺被膜为一层薄的肌纤维，里面具有许多分泌细胞；缠卵腺被膜为单层扁平上皮，下层为环肌，腺体组织由分泌小管构成。蛋白腺主要由皮质层和导管层组成，皮质层内充满了分泌细胞，导管层由许多分泌小管构成，管壁为柱状腺细胞。

Histology of the Reproductive System in Bullacta exarata

Bullacta exarata is a hermaphrodite. The reproductive system consists of mating and genital organs. The mating organs are composed of a stimulator, penis and the protective gland; the genital organs are composed of a digenetic gland, a nidamental gland, a mucous gland and an albumin gland. There are strong muscular layers in the stimulator and penis. The walls of cavities are stratified columnar ciliated epithelium. The muscular layers mainly consist of circular muscles, and the base of the epithelia is composed of connective tissues. The protective gland is a multiple branched tubular gland surrounded by a thin muscular coat. The nidamental gland includes many secretory tubules, coated by thin circular muscles and a simple squamous epithelium. The albumin gland includes the cortex and medulla layer. The cells of the cortex layer are full of secretion. The wall of the vessel is simple columnar ciliated epithelium in the medulla layer.